Method of manufacturing semiconductor device, substrate processing apparatus, and recording medium

ABSTRACT

There is provided a technique that includes providing a substrate; and forming a film on the substrate by performing: supplying a first inert gas from a first supplier to the substrate; supplying a second inert gas from a second supplier to the substrate; and supplying a first processing gas from a third supplier, which is installed on an opposite side of the first supplier across a straight line passing through the second supplier and a center of the substrate, to the substrate, wherein in the act of forming the film, a substrate in-plane film thickness distribution of the film formed on the substrate is adjusted by controlling a balance between a flow rate of the first inert gas supplied from the first supplier and a flow rate of the second inert gas supplied from the second supplier.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromU.S. Non-Provisional patent application Ser. No. 16/190,834, filed Nov.14, 2018, and Japanese Patent Application No. 2017-220187, filed on Nov.15, 2017, the entire contents of which are incorporated herein byreference.

TECHNICAL FIELD

The present disclosure relates to a method of manufacturing asemiconductor device, a substrate processing apparatus, and a recordingmedium.

BACKGROUND

As one of the processes of manufacturing a semiconductor device, aprocess of forming a film on a substrate may be performed.

SUMMARY

Some embodiments of the present disclosure provide a technique capableof controlling the substrate in-plane film thickness distribution of afilm formed on a substrate.

According to one embodiment of the present disclosure, there is provideda technique that includes providing a substrate; and forming a film onthe substrate by performing: supplying a first inert gas from a firstsupplier to the substrate; supplying a second inert gas from a secondsupplier to the substrate; and supplying a first processing gas from athird supplier, which is installed on an opposite side of the firstsupplier across a straight line passing through the second supplier anda center of the substrate, to the substrate, wherein in the act offorming the film, a substrate in-plane film thickness distribution ofthe film formed on the substrate is adjusted by controlling a balancebetween a flow rate of the first inert gas supplied from the firstsupplier and a flow rate of the second inert gas supplied from thesecond supplier.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic configuration diagram of a vertical processfurnace of a substrate processing apparatus suitably used in anembodiment of the present disclosure, in which a part of the processfurnace is shown in a vertical sectional view.

FIG. 2 is a schematic configuration diagram of a part of a verticalprocess furnace of a substrate processing apparatus suitably used in anembodiment of the present disclosure, in which a part of the processfurnace is shown in a sectional view taken along line A-A in FIG. 1.

FIG. 3 is a schematic configuration diagram of a controller of asubstrate processing apparatus suitably used in an embodiment of thepresent disclosure, in which a control system of the controller is shownin a block diagram.

FIG. 4 is a diagram showing a film-forming sequence according to anembodiment of the present disclosure.

FIGS. 5A and 5B are horizontal sectional views showing modifications ofa vertical process furnace, respectively, in which a reaction tube, abuffer chamber, a nozzle and the like are shown in a partially extractedstate.

FIGS. 6A and 6B are diagrams showing film thickness measurement resultsat the outer peripheral portions of substrates for the films formed onthe substrates.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be now described in detailwith reference to the drawings. Like or equivalent components, members,and processes illustrated in each drawing are given like referencenumerals and a repeated description thereof will be properly omitted.Further, the embodiments are presented by way of example only, and arenot intended to limit the present disclosure, and any feature orcombination thereof described in the embodiments may not necessarily beessential to the present disclosure.

One Embodiment of the Present Disclosure

An embodiment of the present disclosure will now be described withreference to FIGS. 1 to 4.

(1) Configuration of Substrate Processing Apparatus

As shown in FIG. 1, a process furnace 202 includes a heater 207 as aheating mechanism (temperature adjustment part). The heater 207 has acylindrical shape and is vertically installed by being supported by aholding plate. The heater 207 also functions as an activation mechanism(excitation part) that thermally activates (excites) a gas.

Inside the heater 207, a reaction tube 203 is arranged concentricallywith the heater 207. The reaction tube 203 is made of a heat-resistantmaterial such as, for example, quartz (SiO₂) or silicon carbide (SiC)and is formed in a cylindrical shape with its upper end closed and itslower end opened. Under the reaction tube 203, a manifold 209 isdisposed concentrically with the reaction tube 203. The manifold 209 ismade of a metallic material such as, for example, stainless steel (SUS)or the like and is formed in a cylindrical shape with its upper andlower ends opened. The upper end portion of the manifold 209 is engagedwith the lower end portion of the reaction tube 203 and is configured tosupport the reaction tube 203. An O-ring 220 a as a seal member isinstalled between the manifold 209 and the reaction tube 203. Thereaction tube 203 is vertically installed just like the heater 207. Aprocess container (reaction container) mainly includes the reaction tube203 and the manifold 209. A process chamber 201 is formed in the hollowportion of the process container. The process chamber 201 is configuredto be able to accommodate wafers 200 as substrates. A process on thewafers 200 is performed in the process chamber 201.

In the process chamber 201, nozzles 249 a to 249 c as first to thirdsuppliers are respectively installed so as to penetrate the side wall ofthe manifold 209. Gas supply pipes 232 a to 232 c are connected to thenozzles 249 a to 249 c, respectively. The nozzles 249 a to 249 c arerespectively different nozzles. Each of the nozzles 249 a and 249 c isinstalled adjacent to the nozzle 249 b.

Mass flow controllers (MFCs) 241 a to 241 c as flow rate controllers(flow rate control parts) and valves 243 a to 243 c as opening/closingvalves are respectively installed in the gas supply pipes 232 a to 232 csequentially from the upstream side of a gas flow. Gas supply pipes 232d and 232 e are connected to the gas supply pipes 232 a and 232 b,respectively, on the downstream side of the valves 243 a and 243 b. Gassupply pipes 232 f and 232 g are respectively connected to the gassupply pipe 232 c on the downstream of the valve 243 c. In the gassupply pipes 232 d to 232 g, MFCs 241 d to 241 g and valves 243 d to 243g are installed sequentially from the upstream side of a gas flow.

As shown in FIG. 2, the nozzles 249 a to 249 c are arranged in anannular space in a plan view between the inner wall of the reaction tube203 and the wafers 200 and are installed so as to extend upward in thearrangement direction of the wafers 200 from the lower portion of theinner wall of the reaction tube 203 to the upper portion thereof. Inother words, the nozzles 249 a to 249 c are respectively installed in aregion existing on the side of a wafer arrangement region, in which thewafers 200 are arranged, and horizontally surrounding the waferarrangement region, so as to extend along the wafer arrangement region.In a plan view, the nozzle 249 b is disposed so as to be opposed to abelow-described exhaust port 231 a on a straight line across the centersof the wafers 200, which is interposed between the nozzle 249 b and theexhaust port 231 a, loaded into the process chamber 201. The nozzles 249a and 249 c are arranged so as to sandwich a straight line L, thatpasses through the nozzle 249 b and the center of the exhaust port 231a, from both sides along the inner wall of the reaction tube 203 (theouter peripheral portions of the wafers 200). The straight line L isalso a straight line passing through the nozzle 249 b and the centers ofthe wafers 200. That is, it can be said that the nozzle 249 c isinstalled on the side opposite to the nozzle 249 a across the straightline L. The nozzles 249 a and 249 c are arranged line-symmetrically withrespect to the straight line L as an axis of symmetry. Gas supply holes250 a to 250 c for supplying gases are formed on the side surfaces ofthe nozzles 249 a to 249 c, respectively. Each of the gas supply holes250 a to 250 c is opened so as to oppose (face) the exhaust port 231 ain a plan view and is capable of supplying a gas toward the wafers 200.The gas supply holes 250 a to 250 c are formed in a plural number fromthe lower portion to the upper portion of the reaction tube 203.

From the gas supply pipe 232 a, a processing gas (second processinggas), for example, a silane-based gas containing silicon (Si) as a mainelement constituting a seed layer to be described later is supplied intothe process chamber 201 via the MFC 241 a, the valve 243 a, and thenozzle 249 a. As the silane-based gas, it may be possible to use ahalogen-element-free silicon hydride gas, for example, a disilane(Si₂H₆, abbreviation: DS) gas.

From the gas supply pipe 232 b, a processing gas (third processing gas),for example, a gas containing Si and a halogen element, i.e., ahalosilane-based gas is supplied into the process chamber 201 via theMFC 241 b, the valve 243 b and the nozzle 249 b. The halogen elementincludes chlorine (Cl), fluorine (F), bromine (Br), iodine (I), and thelike. As the halosilane-based gas, it may be possible to use achlorosilane-based gas containing Si and Cl, for example, adichlorosilane (SiH₂Cl₂, abbreviation: DCS) gas.

From the gas supply pipe 232 c, a processing gas (first processing gas),for example, a silane-based gas containing Si as a main elementconstituting a film formed on each of the wafers 200 is supplied intothe process chamber 201 via the MFC 241 c, the valve 243 c and thenozzle 249 c. As the silane-based gas, it may be possible to use ahalogen-element-free silicon hydride gas, for example, a monosilane(SiH₄, abbreviation: MS) gas.

From the gas supply pipes 232 d to 232 f, an inert gas, for example, anitrogen (N₂) gas is supplied into the process chamber 201 via the MFCs241 d to 241 f, the valves 243 d to 243 f, the gas supply pipes 232 a to232 c and the nozzles 249 a to 249 c. The N₂ gas functions as a purgegas, a carrier gas, a dilution gas and the like, and further functionsas a film thickness distribution control gas for controlling thein-plane film thickness distribution of the film formed on each of thewafers 200.

From the gas supply pipe 232 g, a dopant gas, for example, a gascontaining an impurity (dopant) is supplied into the process chamber 201via the MFC 241 g, the valve 243 g, the gas supply pipe 232 c and thenozzle 249 c. As the dopant gas, it is possible to use a gas containingan element which is one of a group III element (group 13 element) and agroup V element (group 15 element) and which becomes solid by itself,for example, a phosphine (PH₃, abbreviation: PH) gas which is a gascontaining a group V element.

A processing gas supply system mainly includes the gas supply pipes 232a to 232 c, the MFCs 241 a to 241 c and the valves 243 a to 243 c. Thegas supply pipe 232 g, the MFC 241 g and the valve 243 g may be includedin the processing gas supply system. Further, an inert gas supply systemmainly includes the gas supply pipes 232 d to 232 f, the MFCs 241 d to241 f and the valves 243 d to 243 f. In this specification, the gassupply system including the gas supply pipe 232 d, the MFC 241 d and thevalve 243 d is also referred to as a first supply system. The gas supplypipe 232 a, the MFC 241 a and the valve 243 a may be included in thefirst supply system. The gas supply system including the gas supply pipe232 e, the MFC 241 e and the valve 243 e is also referred to as a secondsupply system. The gas supply pipe 232 b, the MFC 241 b and the valve243 b may be included in the second supply system. The gas supply systemincluding the gas supply pipe 232 c, the MFC 241 c and the valve 243 cis also referred to as a third supply system. The gas supply pipes 232 gand 232 f, the MFCs 241 g and 241 f, and the valves 243 g and 243 f maybe included in the third supply system.

One or all of the above-mentioned various supply systems may beconfigured as an integrated supply system 248 formed by integrating thevalves 243 a to 243 g, the MFCs 241 a to 241 g and the like. Theintegrated supply system 248 is connected to each of the gas supplypipes 232 a to 232 g and is configured so that the supply operations ofthe various gases to the gas supply pipes 232 a to 232 g, i.e., theopening/closing operation of the valves 243 a to 243 g, the flow rateadjustment operation of the MFCs 241 a to 241 g, and the like can becontrolled by a controller 121 which will be described later. Theintegrated supply system 248 may be formed of one-piece-type orsplit-type integrated units. The integrated supply system 248 may beattached to and detached from the gas supply pipes 232 a to 232 g or thelike on an integrated unit basis. The maintenance, replacement,expansion or the like of the integrated supply system 248 may beperformed on an integrated unit basis.

An exhaust port 231 a for exhausting the atmosphere inside the processchamber 201 is installed in the lower portion of the side wall of thereaction tube 203. As shown in FIG. 2, the exhaust port 231 a isinstalled at a position opposed to (facing) the nozzles 249 a to 249 c(gas supply holes 250 a to 250 c) across the wafers 200 in a plan view.The exhaust port 231 a may be installed to extend from the lower portionto the upper portion of the side wall of the reaction tube 203, i.e.,along the wafer arrangement region. An exhaust pipe 231 is connected tothe exhaust port 231 a. A vacuum pump 246 as a vacuum-exhaust device isconnected to the exhaust pipe 231 via a pressure sensor 245 as apressure detector (pressure detection part) for detecting the pressureinside the process chamber 201 and an APC (Auto Pressure Controller)valve 244 as a pressure regulator (pressure regulation part). The APCvalve 244 is configured so that the vacuum-exhaust of the interior ofthe process chamber 201 and the stop of the vacuum-exhaust can beperformed by opening and closing the APC valve 244 in a state in whichthe vacuum pump 246 is operated, and so that the pressure inside theprocess chamber 201 can be adjusted by adjusting the valve openingdegree based on the pressure information detected by the pressure sensor245 in a state in which the vacuum pump 246 is operated. An exhaustsystem mainly includes the exhaust pipe 231, the APC valve 244 and thepressure sensor 245. The vacuum pump 246 may be included in the exhaustsystem.

A seal cap 219 as a furnace opening lid capable of airtightly closingthe lower end opening of the manifold 209 is installed below themanifold 209. The seal cap 219 is made of a metallic material such as,for example, stainless steel or the like and is formed in a disc shape.On the upper surface of the seal cap 219, there is installed an O-ring220 b as a seal member which makes contact with the lower end of themanifold 209. Under the seal cap 219, there is installed a rotationmechanism 267 for rotating a boat 217 to be described later. A rotatingshaft 255 of the rotation mechanism 267 passes through the seal cap 219and is connected to the boat 217. The rotation mechanism 267 isconfigured to rotate the wafers 200 by rotating the boat 217. The sealcap 219 is configured to be raised and lowered in the vertical directionby a boat elevator 115 as an elevating mechanism installed outside thereaction tube 203. The boat elevator 115 is configured as a transferdevice (transfer mechanism) that loads and unloads (transfers) thewafers 200 into and out of the process chamber 201 by raising andlowering the seal cap 219. Under the manifold 209, there is installed ashutter 219 s as a furnace opening lid capable of airtightly closing thelower end opening of the manifold 209 in a state in which the seal cap219 is lowered to unload the boat 217 from the process chamber 201. Theshutter 219 s is made of a metallic material such as, for example,stainless steel or the like and is formed in a disk shape. On the uppersurface of the shutter 219 s, there is installed an O-ring 220 c as aseal member which makes contact with the lower end of the manifold 209.The opening/closing operations (the elevating operation, the rotatingoperation and the like) of the shutter 219 s are controlled by a shutteropening/closing mechanism 115 s.

The boat 217 serving as a substrate support is configured to support aplurality of wafers 200, e.g., 25 to 200 wafers 200 in such a state thatthe wafers 200 are arranged in a horizontal posture and in multiplestages along a vertical direction with the centers of the wafers 200aligned with one another. The boat 217 is made of a heat-resistantmaterial such as, for example, quartz or SiC. Heat insulating plates 218made of a heat-resistant material such as, for example, quartz or SiCare disposed at multiple stages in the lower portion of the boat 217.

In the reaction tube 203, there is installed a temperature sensor 263 asa temperature detector. By adjusting the state of supplying electricpower to the heater 207 based on the temperature information detected bythe temperature sensor 263, the temperature inside the process chamber201 is controlled to have a desired temperature distribution. Thetemperature sensor 263 is installed along the inner wall of the reactiontube 203.

As shown in FIG. 3, the controller 121 as a control part (control means)is configured as a computer including a CPU (Central Processing Unit)121 a, a RAM (Random Access Memory) 121 b, a memory device 121 c and anI/O port 121 d. The RAM 121 b, the memory device 121 c and the I/O port121 d are configured to exchange data with the CPU 121 a via an internalbus 121 e. An input/output device 122 formed of, for example, a touchpanel or the like is connected to the controller 121.

The memory device 121 c is configured by, for example, a flash memory, ahard disc drive (HDD), or the like. A control program for controllingthe operations of the substrate processing apparatus, a process recipein which sequences and conditions of a substrate processing process tobe described later are written, and the like are readably stored in thememory device 121 c. The process recipe functions as a program forcausing the controller 121 to execute each sequence in the substrateprocessing process, which will be described later, to obtain apredetermined result. Hereinafter, the process recipe and the controlprogram will be generally and simply referred to as a program. Further,the process recipe will be simply referred to as a recipe. When the term“program” is used herein, it may indicate a case of including only theprocess recipe, a case of including only the control program, or a caseof including both the process recipe and the control program. The RAM121 b is configured as a memory area (work area) in which a program ordata read by the CPU 121 a is temporarily stored.

The I/O port 121 d is connected to the MFCs 241 a to 241 g, the valves243 a to 243 g, the pressure sensor 245, the APC valve 244, the vacuumpump 246, the temperature sensor 263, the heater 207, the rotationmechanism 267, the boat elevator 115, the shutter opening/closingmechanism 115 s, and the like.

The CPU 121 a is configured to read the control program from the memorydevice 121 c and execute the same. The CPU 121 a is also configured toread the process recipe from the memory device 121 c according to aninput of an operation command from the input/output device 122 or thelike. The CPU 121 a is configured to control, according to the contentsof the process recipe thus read, the flow rate adjustment operation ofvarious gases by the MFCs 241 a to 241 g, the opening/closing operationof the valves 243 a to 243 g, the opening/closing operation of the APCvalve 244, the pressure regulation operation performed by the APC valve244 based on the pressure sensor 245, the driving and stopping of thevacuum pump 246, the temperature adjustment operation performed by theheater 207 based on the temperature sensor 263, the operation ofrotating the boat 217 with the rotation mechanism 267 and adjusting therotation speed of the boat 217, the operation of raising and loweringthe boat 217 with the boat elevator 115, the opening/closing operationof the shutter 219 s by the shutter opening/closing mechanism 115 s, andthe like.

The controller 121 may be configured by installing, in a computer, theabove-described program stored in an external memory device 123. Theexternal memory device 123 includes, for example, a magnetic disk suchas an HDD or the like, an optical disk such as a CD or the like, amagneto-optical disk such as an MO or the like, a semiconductor memorysuch as a USB memory or the like, and so forth. The memory device 121 cor the external memory device 123 is configured as a non-transitorycomputer-readable recording medium. Hereinafter, the memory device 121 cand the external memory device 123 will be generally and simply referredto as a recording medium. When the term “recording medium” is usedherein, it may indicate a case of including only the memory device 121c, a case of including only the external memory device 123, or a case ofincluding both the memory device 121 c and the external memory device123. The provision of the program to the computer may be performed byusing a communication means such as the Internet or a dedicated linewithout using the external memory device 123.

(2) Substrate Processing Process

An example of a substrate processing sequence for forming a film on asubstrate, i.e., an example of a film formation sequence will bedescribed with reference to FIG. 4 as one of the processes ofmanufacturing a semiconductor device using the substrate processingapparatus described above. In the following description, the operationsof the respective parts constituting the substrate processing apparatusare controlled by the controller 121.

In the film formation sequence shown in FIG. 4, there is performed astep (Si film formation step) of forming a Si-containing film added(doped) with P, i.e., a P-doped Si film, on a wafer 200, by preparingthe wafer 200 as a substrate, then supplying an N₂ gas as an inert gasto the wafer 200 from a nozzle 249 a as a first supplier, supplying anN₂ gas as an inert gas to the wafer 200 from a nozzle 249 b as a secondsupplier, and supplying an MS gas as a first processing gas and a PH gasas a dopant gas to the wafer 200 from a nozzle 249 c as a third supplierinstalled on the opposite side of the nozzle 249 a across a straightline L passing through the nozzle 249 b and the center of the wafer 200in a plan view. In this specification, the P-doped Si film is alsosimply referred to as a Si film.

In the film formation sequence shown in FIG. 4, after preparing thewafer 200 and before performing the Si film formation step describedabove, there is performed a step (seed layer formation step) of forminga layer containing Si, i.e., a Si layer as a seed layer on the wafer200, by supplying a DS gas as a second processing gas to the wafer 200from the nozzle 249 a, supplying an N₂ gas to the wafer 200 from thenozzle 249 b and supplying an N₂ gas to the wafer 200 from the nozzle249 c. Hereinafter, this Si layer is also referred to as a Si seedlayer.

Specifically, in the seed layer formation step, a cycle of alternatelyperforming step 1 of supplying a DCS gas as a third processing gas tothe wafer 200 from any one of the nozzles 249 a to 249 c (in this case,the nozzle 249 b) and step 2 of supplying a DS gas to the wafer 200 fromthe nozzle 249 a, supplying an N₂ gas to the wafer 200 from the nozzle249 b and supplying an N₂ gas to the wafer 200 from the nozzle 249 c isperformed a predetermined number of times.

In the above-described Si film formation step, the wafer in-plane filmthickness distribution of the Si film formed on the wafer 200(hereinafter also simply referred to as an in-plane film thicknessdistribution) is adjusted by controlling the balance between the flowrate of the N₂ gas supplied from the nozzle 249 a and the flow rate ofthe N₂ gas supplied from the nozzle 249 b.

As an example, description will now be made on an example where a barewafer having a small surface area with no concavo-convex structureformed on the surface thereof is used as the wafer 200 and the in-planefilm thickness distribution of the Si film is adjusted by the filmformation sequence and the flow rate control described above. In thisspecification, the in-plane film thickness distribution of a film whichis thickest at the central portion of the wafer 200 and graduallybecomes thinner toward the outer peripheral portion (peripheral edgeportion) is also referred to as a center convex distribution. Further,the in-plane film thickness distribution of a film which is thinnest atthe central portion of the wafer 200 and becomes gradually thickertowards the outer peripheral portion is also referred to as a centerconcave distribution. Moreover, the film thickness distribution of aflat film with little film thickness variation from the central portionto the outer peripheral portion of the wafer 200 is also referred to asa flat distribution. If a film having a center convex distribution canbe formed on a bare wafer, it is possible to form a film having a flatdistribution on a pattern wafer (product wafer) having a large surfacearea with a fine concavo-convex structure formed on the surface thereof.

In this specification, the film formation sequence shown in FIG. 4 maybe denoted as follows for the sake of convenience. The same notation isalso used in the following description of modifications and the like.(DCS→DS)×n→MS+PH⇒P-doped Si

When the term “wafer” is used herein, it may refer to “a wafer itself”or “a laminated body of a wafer and a predetermined layer or film formedon the surface of the wafer.” Furthermore, when the phrase “a surface ofa wafer” is used herein, it may refer to “a surface of a wafer itself”or “a surface of a predetermined layer or the like formed on a wafer.”Moreover, the expression “a predetermined layer is formed on a wafer” asused herein may mean that “a predetermined layer is directly formed on asurface of a wafer itself” or that “a predetermined layer is formed on alayer or the like formed on a wafer.” In addition, when the term“substrate” is used herein, it may be synonymous with the term “wafer.”

(Wafer Charging and Boat Loading)

When a plurality of wafers 200 is charged on the boat 217 (wafercharging), the shutter 219 s is moved by the shutter opening/closingmechanism 115 s to open the lower end opening of the manifold 209(shutter open). Thereafter, as shown in FIG. 1, the boat 217 supportingthe plurality of wafers 200 is lifted up by the boat elevator 115 and isloaded into the process chamber 201 (boat loading). In this state, theseal cap 219 seals the lower end of the manifold 209 via the O-ring 220b.

(Pressure Regulation and Temperature Adjustment)

The interior of the process chamber 201, namely the space in which thewafers 200 exist, is vacuum-exhausted (depressurization-exhausted) bythe vacuum pump 246 so as to reach a desired pressure (degree ofvacuum). At this time, the pressure in the process chamber 201 ismeasured by the pressure sensor 245. The APC valve 244 isfeedback-controlled based on the measured pressure information. Thewafers 200 in the process chamber 201 are heated by the heater 207 to adesired film-forming temperature. At this time, the state of supplyingelectric power to the heater 207 is feedback-controlled based on thetemperature information detected by the temperature sensor 263 such thatthe interior of the process chamber 201 has a desired temperaturedistribution. In addition, the rotation of the wafers 200 by therotation mechanism 267 begins. The exhaustion of the process chamber 201and the heating and rotation of the wafers 200 may be continuouslyperformed at least until the processing of the wafers 200 is completed.

(Seed Layer Formation Step)

Thereafter, the following steps 1 and 2 are sequentially executed.

[Step 1]

In this step, a DCS gas is supplied from the nozzle 249 b to the wafer200 in the process chamber 201, and an N₂ gas is supplied from each ofthe nozzles 249 a and 249 c to the wafer 200.

Specifically, the valve 243 b is opened and the DCS gas is allowed toflow into the gas supply pipe 232 b. The flow rate of the DCS gas isadjusted by the MFC 241 b. The DCS gas is supplied into the processchamber 201 via the nozzle 249 b and is exhausted from the exhaust port231 a. At this time, the DCS gas is supplied to the wafer 200.Furthermore, at this time, the valves 243 d and 243 f are opened and theN₂ gas is supplied into the process chamber 201 via each of the nozzles249 a and 249 c.

By supplying the DCS gas to the wafer 200 under the processingconditions to be described later, it is possible to remove a naturaloxide film, impurities, etc. from the surface of the wafer 200 by thetreatment action (etching action) possessed by the DCS gas. This makesit possible to clean the surface of the wafer 200. Thus, the surface ofthe wafer 200 can become a surface on which the adsorption of Si, i.e.,the formation of a seed layer easily proceeds in step 2 to be describedlater.

After the surface of the wafer 200 is cleaned, the valve 243 b is closedand the supply of the DCS gas into the process chamber 201 is stopped.Then, the inside of the process chamber 201 is vacuum-exhausted and thegas or the like remaining in the process chamber 201 is removed from theinside of the process chamber 201. At this time, the valves 243 d to 243f are opened and the N₂ gas is supplied into the process chamber 201 viathe nozzles 249 a to 249 c. The N₂ gas supplied from the nozzles 249 ato 249 c acts as a purge gas, whereby the interior of the processchamber 201 is purged (purging step).

[Step 2]

After step 1 is finished, a DS gas is supplied from the nozzle 249 a tothe surface of the wafer 200 existing in the process chamber 201, i.e.,the surface of the cleaned wafer 200, and an N₂ gas is supplied fromeach of the nozzles 249 b and 249 c.

Specifically, the valve 243 a is opened and the DS gas is allowed toflow into the gas supply pipe 232 a. The flow rate of the DS gas isadjusted by the MFC 241 a. The DS gas is supplied into the processchamber 201 via the nozzle 249 a and is exhausted from the exhaust port231 a. At this time, the DS gas is supplied to the wafer 200.Furthermore, at this time, the valves 243 e and 243 f are opened and theN₂ gas is supplied into the process chamber 201 via each of the nozzles249 b and 249 c.

By supplying the DS gas to the wafer 200 under the processing conditionsto be described later, it is possible to allow Si contained in the DSgas to be adsorbed on the surface of the wafer 200 cleaned in step 1 andto form seeds (nuclei) on the surface of the wafer 200. Under theprocessing conditions to be described later, the crystal structure ofthe nuclei formed on the surface of the wafer 200 is amorphous.

After the nucleus is formed on the surface of the wafer 200, the valve243 a is closed and the supply of the DS gas into the process chamber201 is stopped. Then, the gas or the like remaining in the processchamber 201 is removed from the inside of the process chamber 201 by thesame processing procedure as in the purging step of step 1.

[Performed a Predetermined Number of Times]

By performing a cycle, which performs the above-described steps 1 and 2alternately, i.e., non-synchronously without synchronizing steps 1 and2, a predetermined number of times (n times where n is an integer of 1or more), it is possible to form a seed layer having the aforementionednuclei arranged at a high density, i.e., an Si seed layer on the wafer200.

An example of processing conditions used in step 1 is described asfollows.

DCS gas supply flow rate: 10 to 1000 sccm

DCS gas supply time: 0.5 to 10 minutes

N₂ gas supply flow rate (per gas supply pipe): 10 to 10000 sccm

Processing temperature (first temperature): 350 to 450 degrees C.

Processing pressure: 400 to 1000 Pa

An example of processing conditions used in step 2 is described asfollows.

DS gas supply flow rate: 10 to 1000 sccm

DS gas supply time: 0.5 to 10 minutes

Other processing conditions are the same as the processing conditionsused in step 1.

In step 1, as the third processing gas, in addition to the DCS gas, itmay be possible to use a chlorosilane-based gas such as amonochlorosilane (SiH₃Cl, abbreviation: MCS) gas, a tetrachlorosilane(SiCl₄, abbreviation: STC) gas, a trichlorosilane (SiHCl₃, abbreviation:TCS) gas, a hexachlorodisilane (Si₂Cl₆, abbreviation: HCDS) gas, anoctachlorotrisilane (Si₃Cl₈, abbreviation: OCTS) gas or the like.Furthermore, as the third processing gas, it may be possible to use atetrafluorosilane (SiF₄) gas, a tetrabromosilane (SiBr₄) gas, atetraiodosilane (SiI₄) gas or the like. That is, as the third processinggas, in addition to the chlorosilane-based gas, it may be possible touse a halosilane-based gas such as a fluorosilane-based gas, abromosilane-based gas, an iodosilane-based gas or the like. In addition,as the third processing gas, it may be possible to use an Si-freehalogen-based gas such as a hydrogen chloride (HCl) gas, a chlorine(Cl₂) gas, a trichloroborane (BCl₃) gas, a chlorine fluoride (ClF₃) gasor the like.

In step 2, as the second processing gas, in addition to the DS gas, itmay be possible to use a silicon hydride gas such as an MS gas, atrisilane (Si₃H₈) gas, a tetrasilane (Si₄H₁₀) gas, a pentasilane(Si₅H₁₂) gas, a hexasilane (Si₆H₁₄) gas or the like.

As the inert gas, in addition to the N₂ gas, it may be possible to use arare gas such as an Ar gas, a He gas, a Ne gas, a Xe gas or the like.This also applies to a temperature raising step, a Si film formationstep and the like which will be described later.

(Temperature Raising Step)

After the seed layer formation step is finished, the output of theheater 207 is adjusted so that the temperature inside the processchamber 201 is changed to a second temperature higher than theaforementioned first temperature. When this step is performed, thevalves 243 d to 243 f are opened and the N₂ gas is supplied into theprocess chamber 201 via the nozzles 249 a to 249 c to purge the insideof the process chamber 201. After the temperature inside the processchamber 201 reaches the second temperature and becomes stable, the Sifilm formation step to be described later is started.

(Si Film Formation Step)

In this step, an MS gas and a PH gas are supplied from the nozzle 249 cto the wafer 200 in the process chamber 201, i.e., the surface of theseed layer formed on the wafer 200, and an N₂ gas is supplied from eachof the nozzles 249 a and 249 b.

Specifically, the valve 243 c is opened and the MS gas is allowed toflow into the gas supply pipe 232 c. The flow rate of the MS gas isadjusted by the MFC 241 c. The MS gas is supplied into the processchamber 201 via the nozzle 249 c and is exhausted from the exhaust port231 a. At this time, the valve 243 g is opened and the PH gas is allowedto flow into the gas supply pipe 232 g. The flow rate of the PH gas isadjusted by the MFC 241 g. The PH gas is supplied into the processchamber 201 via the gas supply pipe 232 c and the nozzle 249 c and isexhausted from the exhaust port 231 a. At this time, the MS gas and thePH gas are supplied simultaneously to the wafer 200. Furthermore, atthis time, the valves 243 d and 243 e are opened and the N₂ gas issupplied into the process chamber 201 via each of the nozzles 249 a and249 b.

By supplying the MS gas and the PH gas to the wafer 200 from the nozzle249 c under the processing conditions described later, it is possible tocause Si to be adsorbed (deposited) on the surface of the wafer 200,i.e., on the seed layer formed on the wafer 200, thereby forming aP-doped Si film. Under the processing conditions described later, thecrystal structure of the Si film formed on the wafer 200 becomesamorphous, polycrystalline or an amorphous/polycrystalline mixedstructure.

When supplying the MS gas or the PH gas (hereinafter also referred to asMS gas or the like) to the wafer 200, the balance between the flow rateof the N₂ gas supplied from the nozzle 249 a and the flow rate of the N₂gas supplied from the nozzle 249 b is controlled. Specifically, forexample, the flow rate of the N₂ gas supplied from the nozzle 249 a ismade different from the flow rate of the N₂ gas supplied from the nozzle249 b. This makes it possible to adjust the in-plane film thicknessdistribution of the Si film formed on the wafer 200.

In the film formation sequence shown in FIG. 4, as an example, there isshown a case where the flow rate of the N₂ gas supplied from the nozzle249 a is made larger than the flow rate of the N₂ gas supplied from thenozzle 249 b. In this case, for example, the flow rate of the N₂ gassupplied from the nozzle 249 a is set to 500 to 2000 sccm and the flowrate of the N₂ gas supplied from the nozzle 249 b is set to 10 to 400sccm. By controlling the flow rate balance in this way, it is possibleto control the wafer in-plane concentration distribution (partialpressure distribution) of the MS gas or the like supplied to the wafer200, i.e., the supply amount distribution of the MS gas or the like inthe wafer plane. More specifically, the concentration (supply amount) ofthe MS gas or the like supplied to the central portion of the wafer 200may be controlled in an increasing direction, and the concentration(supply amount) of the MS gas or the like supplied to the outerperipheral portion of the wafer 200 is controlled in a decreasingdirection. Depending on the degree of the control, the concentration(supply amount) of the MS gas or the like supplied to the centralportion of the wafer 200 may be set to the same level as theconcentration (supply amount) of the MS gas or the like supplied to theouter peripheral portion of the wafer 200, or may be set to be largerthan the concentration (supply amount) of the MS gas or the likesupplied to the outer peripheral portion of the wafer 200. As a result,it becomes possible to bring the in-plane film thickness distribution ofthe Si film formed on the wafer 200 closer to a flat distribution or toa center convex distribution from a center concave distribution.

After the Si film having a desired in-plane film thickness distributionis formed on the wafer 200, the valves 243 c and 243 g are closed andthe supply of the MS gas and the PH gas into the process chamber 201 isstopped. Then, the gas and the like remaining in the process chamber 201are removed from the inside of the process chamber 201 by the sameprocessing procedure as that of the purging step of the above-describedstep 1.

An example of processing conditions used in the Si film formation stepis described as follows.

MS gas supply flow rate: 10 to 2000 sccm

PH gas supply flow rate: 0.1 to 500 sccm

MS gas and PH gas supply time: 1 to 300 minutes

N₂ gas supply flow rate (per gas supply pipe): 10 to 20000 sccm

Processing temperature (second temperature): 500 to 650 degrees C.

Processing pressure: 30 to 200 Pa

The processing conditions shown here are the conditions under which theMS gas is thermally decomposed in the process chamber 201 when the MSgas exists alone, i.e., the conditions under which a CVD reactionoccurs. That is, the processing conditions shown here are the conditionsunder which no self-limit is imposed on adsorption (deposition) of Si onthe wafer 200, i.e., the conditions under which the adsorption of Si onthe wafer 200 is not self-limited.

As the first processing gas, in addition to the MS gas, it may bepossible to use the various kinds of silicon hydride gases describedabove and the various kinds of the halosilane-based gases describedabove. In order to suppress the remaining of a halogen element in the Sifilm, it is preferable to use a silicon hydride gas as the firstprocessing gas. In order to improve the deposition rate of the Si film,it is preferable to use a highly-reactive halosilane-based gas as thefirst processing gas.

As the dopant gas, in addition to the PH gas, it may be possible to usea gas such as an arsine (AsH₃) gas or the like containing an element (P,arsenic (As) or the like) which is a Group V element and which becomessolid by itself. Furthermore, as the dopant gas, in addition to the gascontaining a Group V element, it may be possible to use a gas such as adiborane (B₂H₆) gas, a trichloroborane (BCl₃) gas or the like containingan element (boron (B) or the like) which is a Group III element andwhich becomes solid by itself.

(After-Purging and Atmospheric Pressure Restoration)

After the Si film formation step is completed, the N₂ gas as a purge gasis supplied from the nozzles 249 a to 249 c into the process chamber 201and is exhausted from the exhaust port 231 a. As a result, the interiorof the process chamber 201 is purged and the gas or the reactionbyproduct remaining in the process chamber 201 is removed from theprocess chamber 201 (after-purging). Thereafter, the atmosphere in theprocess chamber 201 is replaced with an inert gas (inert gasreplacement), and the pressure in the process chamber 201 is restored tothe atmospheric pressure (atmospheric pressure restoration).

(Boat Unloading and Wafer Discharging)

The seal cap 219 is lowered by the boat elevator 115 and the lower endopening of the manifold 209 is opened. Then, the processed wafers 200are unloaded from the lower end of the manifold 209 to the outside ofthe reaction tube 203 in a state in which they are supported by the boat217 (boat unloading). After the boat unloading, the shutter 219 s ismoved so that the lower end opening of the manifold 209 is sealed by theshutter 219 s via the O-ring 220 c (shutter closing). The processedwafers 200 are taken out from the boat 217 after they are unloaded tothe outside of the reaction tube 203 (wafer discharging).

(3) Effects of the Present Embodiment

According to the present embodiment, one or more of the followingeffects may be obtained.

(a) When supplying the MS gas from the nozzle 249 c in the Si filmformation step, by controlling the balance between the flow rate of theN₂ gas supplied from the nozzle 249 a and the flow rate of the N₂ gassupplied from the nozzle 249 b, it is possible to adjust the in-planefilm thickness distribution of the Si film formed on the wafer 200. Forexample, it is possible to set the in-plane film thickness distributionof the Si film formed on the wafer 200 configured as a bare wafer tobecome a center convex distribution. Thus, when a pattern wafer is usedas the wafer 200, it is possible to form a Si film having a flatdistribution on the wafer 200.

Although the in-plane film thickness distribution of the film formed onthe wafer 200 depends on the surface area of the wafer 200, it isconsidered that this is due to the so-called loading effect. When aprecursor such as an MS gas or the like flows from the outer peripheralportion to the central portion of the wafer 200 as in the substrateprocessing apparatus according to the present embodiment, as the surfacearea of the wafer 200 subjected to film formation becomes larger, theprecursor such as the MS gas or the like is consumed in a large amountat the outer peripheral portion of the wafer 200, and thus it becomeshard for the precursor to reach the central portion of the wafer 200. Asa result, the in-plane film thickness distribution of the film formed onthe wafer 200 tends to become a center concave distribution. Accordingto the present embodiment, even when a pattern wafer having a largesurface area is used as the wafer 200, it is possible to correct thein-plane film thickness distribution of the film formed on the wafer 200from a center concave distribution to a flat distribution, ultimately toa center convex distribution. This makes it possible to freely controlthe in-plane film thickness distribution of the film formed on the wafer200.

(b) In the Si film formation step, by supplying the N₂ gas using the twonozzles 249 a and 249 b, as compared with a case where the N₂ gas issupplied using one nozzle, it is possible to precisely and widely adjustthe in-plane film thickness distribution of the Si film to be formed onthe wafer 200. This is because, according to the method of the presentembodiment, it is possible to individually, i.e., independently, controlthe concentration (supply amount) of the MS gas or the like supplied tothe central portion of the wafer 200 and the concentration (supplyamount) of the MS gas or the like supplied to the outer peripheralportion of the wafer 200.(c) By disposing at least the nozzle 249 b, preferably the nozzles 249 ato 249 c so as to be opposed to the exhaust port 231 a at least in aplan view, it is possible to enhance the controllability of the in-planefilm thickness distribution of the Si film formed on the wafer 200.Further, by arranging the nozzles 249 a and 249 c line-symmetricallywith respect to the straight line L as a symmetry axis, it becomespossible to further enhance the controllability of the in-plane filmthickness distribution of the Si film formed on the wafer 200.(d) By performing the seed layer formation step after preparing thewafer 200 and before performing the Si film formation step, it ispossible to shorten the incubation time (growth delay) of the Si filmformed on the wafer 200, thereby improving the productivity of thefilm-forming process.(e) In the seed layer formation step, by alternately performing thesupply of the DCS gas and the supply of the DS gas, it is possible toenhance the formation efficiency of the seed layer and to make the seedlayer dense. This makes it possible to enhance the productivity of thefilm-forming process and to make the Si film formed on the wafer 200dense. In addition, by alternately supplying the gases, it is possibleto suppress excess gas phase reaction in the process chamber 201 and toimprove the quality of the film-forming process.(f) The aforementioned effects may be similarly obtained even when usingthe first processing gas other than the MS gas, using the secondprocessing gas other than the DS gas, using the third processing gasother than the DCS gas, using the dopant gas other than PH gas, andusing the inert gas other than the N₂ gas.

(4) Modification

The film formation step according to the present embodiment is notlimited to the embodiment shown in FIG. 4, but may be changed as in thefollowing modifications. These modifications may be arbitrarilycombined. Unless specifically mentioned otherwise, the processingprocedures and processing conditions in each step of each of themodifications may be the same as the processing procedures andprocessing conditions in each step of the above-described substrateprocessing sequence.

(Modification 1)

In the film formation sequence shown in FIG. 4, there has been describedan example where the seed layer formation step is performed. However,the seed layer formation step may not be performed. Even in thismodification, when the MS gas is supplied from the nozzle 249 c in theSi film formation step, by controlling the balance between the flow rateof the N₂ gas supplied from the nozzle 249 a and the flow rate of the N₂gas supplied from the nozzle 249 b, it becomes possible to adjust thein-plane film thickness distribution of the Si film formed on the wafer200.

(Modification 2)

In the Si film formation step, when the MS gas or the like is suppliedfrom the nozzle 249 c, the flow rate of the N₂ gas supplied from thenozzle 249 a may be smaller than the flow rate of the N₂ gas suppliedfrom the nozzle 249 b. In this case, for example, the flow rate of theN₂ gas supplied from the nozzle 249 a is set to 10 to 400 sccm and theflow rate of the N₂ gas supplied from the nozzle 249 b is set to 500 to2000 sccm. By controlling the flow rate balance in this manner, it ispossible to control the concentration (supply amount) of the MS gas orthe like supplied to the central portion of the wafer 200 in adecreasing direction and to control the concentration (supply amount) ofthe gas or the like supplied to the outer peripheral portion of thewafer 200 in an increasing direction. As a result, it becomes possibleto bring the in-plane film thickness distribution of the Si film formedon the wafer 200 closer to a flat distribution, ultimately to a centerconcave distribution from a center convex distribution.

In the case where the in-plane film thickness distribution of the Sifilm formed on the wafer 200 becomes a desired distribution, when the MSgas or the like is supplied from the nozzle 249 c, the flow rate of theN₂ gas supplied from the nozzle 249 a and the flow rate the N₂ gassupplied from the nozzle 249 b may be made equal to each other withoutmaking them different.

(Modification 3)

In step 2 of the seed layer formation step as well as the Si filmformation step, when the DS gas is supplied from the nozzle 249 a, itmay be possible to control the balance between the flow rate of the N₂gas supplied from the nozzle 249 b and the flow rate of the N₂ gassupplied from the nozzle 249 c. For example, the in-plane thicknessdistribution of the seed layer formed on the wafer 200 may be adjustedby making the flow rate of the N₂ gas supplied from the nozzle 249 bdifferent from the flow rate of the N₂ gas supplied from the nozzle 249c. As a result, it becomes possible to adjust the in-plane filmthickness distribution of the Si film formed on the wafer 200.

For example, when the DS gas is supplied from the nozzle 249 a, the flowrate of the N₂ gas supplied from the nozzle 249 b may be smaller thanthe flow rate of the N₂ gas supplied from the nozzle 249 c. In thiscase, for example, the flow rate of the N₂ gas supplied from the nozzle249 b is set to 10 to 400 sccm and the flow rate of the N₂ gas suppliedfrom the nozzle 249 c is set to 500 to 2000 sccm. By controlling theflow rate balance in this manner, it is possible to bring the in-planethickness distribution of the seed layer formed on the wafer 200 closerto a flat distribution, ultimately to a center convex distribution froma center concave distribution.

Moreover, for example, when the DS gas is supplied from the nozzle 249a, the flow rate of the N₂ gas supplied from the nozzle 249 b may belarger than the flow rate of the N₂ gas supplied from the nozzle 249 c.In this case, for example, the flow rate of the N₂ gas supplied from thenozzle 249 b is set to 500 to 2000 sccm and the flow rate of the N₂ gassupplied from the nozzle 249 c is set to 10 to 400 sccm. By controllingthe flow rate balance in this manner, it is possible to bring thein-plane thickness distribution of the seed layer formed on the wafer200 closer to a flat distribution, ultimately to a center concavedistribution from a center convex distribution.

(Modification 4)

In step 2 of the seed layer formation step, the N₂ gas may be suppliedfrom the nozzle 249 a to the wafer 200, the N₂ gas may be supplied fromthe nozzle 249 b to the wafer 200, and the DS gas may be supplied fromthe nozzle 249 c to the wafer 200. That is, in the Si film formationstep and step 2 of the seed layer formation step, the processing gases(the DS gas and the MS gas) may be supplied from the common nozzle 249c.

In this case, in step 2, when the DS gas is supplied from the nozzle 249c, by controlling the balance between the flow rate of the N₂ gassupplied from the nozzle 249 a and the flow rate of the N₂ gas suppliedfrom the nozzle 249 b, it is possible to adjust the in-plane thicknessdistribution of the seed layer formed on the wafer 200. In this case,the supply conditions of the N₂ gas supplied from each of the nozzles249 a and 249 b can be the same as those in the Si film formation step.

For example, when the DS gas is supplied from the nozzle 249 c, bymaking the flow rate of the N₂ gas supplied from the nozzle 249 a largerthan the flow rate of the N₂ gas supplied from the nozzle 249 b, itbecomes possible to bring the in-plane thickness distribution of theseed layer formed on the wafer 200 closer to a flat distribution,ultimately to a center convex distribution from a center concavedistribution. As a result, it is possible to adjust the in-plane filmthickness distribution of the Si film formed on the wafer 200.

Furthermore, for example, when the DS gas is supplied from the nozzle249 c, by making the flow rate of the N₂ gas supplied from the nozzle249 a smaller than the flow rate of the N₂ gas supplied from the nozzle249 b, it becomes possible to bring the in-plane thickness distributionof the seed layer formed on the wafer 200 closer to a flat distribution,ultimately to a center concave distribution from a center convexdistribution. As a result, it is possible to adjust the in-plane filmthickness distribution of the Si film formed on the wafer 200.

(Modification 5)

In step 1 of the seed layer formation step, the DCS gas may be suppliedto the wafer 200 from any of the nozzles 249 a and 249 c.

In step 1, when supplying the DCS gas from the nozzle 249 c, it may bepossible to control the balance between the flow rate of the N₂ gassupplied from the nozzle 249 a and the flow rate of the N₂ gas suppliedfrom the nozzle 249 b. For example, by making the flow rate of the N₂gas supplied from the nozzle 249 a different from the flow rate of theN₂ gas supplied from the nozzle 249 b, it is possible to make the degreeof cleaning performed on the surface of the wafer 200 different in theplane of the wafer 200. Thus, it is possible to adjust the in-planethickness distribution of the seed layer formed on the wafer 200. As aresult, it is possible to adjust the in-plane film thicknessdistribution of the Si film formed on the wafer 200.

For example, when supplying the DCS gas from the nozzle 249 c, by makingthe flow rate of the N₂ gas supplied from the nozzle 249 a larger thanthe flow rate of the N₂ gas supplied from the nozzle 249 b, the cleaningaction at the central portion of the wafer 200 may be controlled in anincreasing direction and the cleaning action at the outer peripheralportion of the wafer 200 may be controlled in a decreasing direction.This makes it possible to bring the in-plane thickness distribution ofthe seed layer formed on the wafer 200, i.e., the in-plane filmthickness distribution of the Si film formed on the wafer 200 closer toa flat distribution, ultimately to a center convex distribution from acenter concave distribution.

Furthermore, for example, when supplying the DCS gas from the nozzle 249c, by making the flow rate of the N₂ gas supplied from the nozzle 249 asmaller than the flow rate of the N₂ gas supplied from the nozzle 249 b,the cleaning action at the central portion of the wafer 200 may becontrolled in a decreasing direction and the cleaning action at theouter peripheral portion of the wafer 200 may be controlled in anincreasing direction. This makes it possible to bring the in-planethickness distribution of the seed layer formed on the wafer 200, i.e.,the in-plane film thickness distribution of the Si film formed on thewafer 200 closer to a flat distribution, ultimately to a center concavedistribution from a center convex distribution.

When supplying the DCS gas from the nozzle 249 a in step 1, bycontrolling the balance between the flow rate of the N₂ gas suppliedfrom the nozzle 249 b and the flow rate of the N₂ gas supplied from thenozzle 249 c, it is possible to obtain the same effects.

(Modification 6)

In modifications 3 to 5, the flow rate balance control for the N₂ gas inthe Si film formation step may not be performed. Even in this case, itis possible to adjust the in-plane film thickness distribution of the Sifilm formed on the wafer 200 to some extent by adjusting the in-planethickness distribution of the seed layer formed on the wafer 200.

(Modification 7)

As in the film formation sequence shown below, in the seed layerformation step, step 1 may not be performed and step 2 may be performeda predetermined number of times (one or more times). Furthermore, instep 2, as the second processing gas, in addition to the silicon hydridegas, it may be possible to use an aminosilane-based gas such as atetrakisdimethylaminosilane (Si[N(CH₃)₂]₄, abbreviation: 4DMAS) gas, atrisdimethylaminosilane (Si[N(CH₃)₂]₃H, abbreviation: 3DMAS) gas, abisdiethylaminosilane (Si[N(C₂H₅)₂]₂H₂, abbreviation: BDEAS) gas, abis-tertiary-butylaminosilane (SiH₂[NH (C₄H₉)]₂, abbreviation: BTBAS)gas, a diisopropylaminosilane (SiH₃N[CH(CH₃)₂]₂, abbreviation: DIPAS)gas or the like.DIPAS→MS+PH⇒P-doped Si(Modification 8)

As in the film formation sequence shown below, in the seed layerformation step, each of steps 1 and 2 may be performed once. Inaddition, in step 1, in addition to the halosilane-based gas, an Si-freehalogen-based gas such as an HCl gas or the like may be used as thethird processing gas.HCl→DS→MS+PH⇒P-doped Si(Modification 9)

As the first processing gas, in addition to the silicon hydride gas, itmay be possible to use, for example, a chlorosilane-based gas such as aDCS gas, an HCDS gas or the like, or an aminosilane-based gas such as a3DMAS gas, a BDEAS gas or the like.

In addition to the above-described processing gases, as a reactant, itmay be possible to additionally use, for example, an amine-based gassuch as a triethylamine ((C₂H₅)₃N, abbreviation: TEA) gas or the like,an oxygen (O)-containing gas (oxidizing agent) such as an oxygen (O₂)gas, a water vapor (H₂O gas), an ozone (0 ₃) gas, a plasma-excited O₂gas (O₂*), a mixture of an O₂ gas and a hydrogen (H₂) gas or the like, acarbon (C)-containing gas such as a propylene (C₃H₆) gas or the like,and a B-containing gas such as a BCl₃ gas or the like.

For example, according to the film formation sequences shown below, asilicon nitride film (Si film), a silicon oxynitride film (SiON film), asilicon oxycarbide film (SiOC film), a silicon carbonitride film (SiCNfilm), a silicon oxycarbonitride film (SiOCN film), a siliconborocarbonitride film (SiBCN film), a silicon boronitride film (SiBNfilm), and a silicon oxide film (SiO film) may be formed on the wafer200. In the following film formation sequences, when supplying the firstprocessing gas (the DCS gas, the HCDS gas, the 3DMAS gas or the BDEASgas) from the nozzle 249 c, the balance of the flow rates of the N₂gases supplied from the nozzles 249 a and 249 b is controlled in thesame manner as in the film formation sequence shown in FIG. 4 or themodification described above. Thus, the same effects as those of thefilm formation sequence shown in FIG. 4 or the above-describedmodifications are obtained.DCS+NH₃⇒SiN(DCS→NH₃)×n⇒SiN(HCDS→NH₃→O₂)×n⇒SiON(HCDS→TEA→O₂)×n⇒SiOC(N)(HCDS→C₃H₆→NH₃)×n⇒SiCN(HCDS→C₃H₆→NH₃→O₂)×n⇒SiOCN(HCDS→C₃H₆→BCl₃→NH₃)×n⇒SiBCN(HCDS→BCl₃→NH₃)×n⇒SiBN(HCDS→O₂+H₂)×n⇒SiO(3DMAS→O₃)×n⇒SiO(BDEAS→O₂*)×n⇒SiO

An example of processing conditions in the step of supplying the firstprocessing gas in this modification is described as follows.

-   -   First processing gas supply flow rate: 10 to 2000 sccm    -   First processing gas supply time: 1 to 120 seconds    -   Processing temperature: 250-800 degrees C.    -   Processing pressure: 1 to 2666 Pa    -   Other processing conditions are the same as the processing        conditions in the Si film formation step of the film formation        sequence shown in FIG. 4.

An example of processing conditions in the step of supplying thereactant is described as follows.

-   -   Reactant supply flow rate: 100 to 10000 sccm    -   Reactant supply time: 1 to 120 seconds    -   Processing pressure: 1 to 4000 Pa    -   Other processing conditions are the same as the processing        conditions in the step of supplying the first processing gas in        this modification.

Even in this modification, the seed layer formation step may beperformed on the wafer 200 after preparing the wafer 200 and beforeperforming the film formation sequence described above.

Other Embodiments

The embodiment of the present disclosure has been concretely describedabove. However, the present disclosure is not limited to theabove-described embodiment. Various modifications may be made withoutdeparting from the spirit of the present disclosure.

In the above-described embodiment, there has been described an examplewhere the nozzles 249 a to 249 c are installed adjacent to each other(in close proximity with each other). However, the present disclosure isnot limited to such embodiments. For example, the nozzles 249 a and 249c may be installed at the positions away from the nozzle 249 b in theannular space in a plan view between the inner wall of the reaction tube203 and the wafers 200.

In the above-described embodiment, there has been described an examplewhere the first to third suppliers are composed of the nozzles 249 a to249 c and the three nozzles are installed in the process chamber 201.However, the present disclosure is not limited to such embodiments. Forexample, at least one selected from the group of the first to thirdsuppliers may be composed of two or more nozzles. Further, a nozzleother than the first to third suppliers may be newly installed in theprocess chamber 201, and an N₂ gas or various processing gases may befurther supplied using this nozzle. When the nozzle other than thenozzles 249 a to 249 c is installed in the process chamber 201, thenewly installed nozzle may be installed at a position facing the exhaustport 231 a in a plan view or may be installed at a position not facingthe exhaust port 231 a. That is, the newly installed nozzle may belocated at a position spaced apart from the nozzles 249 a to 249 c, forexample, an intermediate position between the nozzles 249 a to 249 c andthe exhaust port 231 a or a position near the intermediate positionalong the outer peripheries of the wafers 200 in the annular space in aplan view between the inner wall of the reaction tube 203 and the wafers200.

In the above-described embodiment, there has been described an examplewhere the film containing Si as a main element is formed on thesubstrate. However, the present disclosure is not limited to suchembodiments. That is, the present disclosure may be suitably applied toa case where a film not containing Si but containing a semimetal elementsuch as germanium (Ge), B or the like as a main element is formed on thesubstrate. The present disclosure may also be suitably applied to a casewhere a film containing a metal element such as titanium (Ti), zirconium(Zr), hafnium (Hf), niobium (Nb), tantalum (Ta), molybdenum (Mo),tungsten (W), yttrium (Y), lanthan (La), strontium (Sr), aluminum (Al)or the like as a main element is formed on the substrate.

It is preferable that the recipes used for substrate processing areindividually prepared according to the processing contents and stored inthe memory device 121 c via the electric communication line or theexternal memory device 123. When starting a process, it is preferablethat the CPU 121 a appropriately selects an appropriate recipe from theplurality of recipes stored in the memory device 121 c according to thesubstrate processing contents. This makes it possible to form films ofvarious film types, composition ratios, film qualities and filmthicknesses with high reproducibility in one substrate processingapparatus. It is also possible to reduce the burden on an operator andto quickly start the process while avoiding operation errors.

The above-described recipes are not limited to the case of newlycreating them, but may be prepared by, for example, changing theexisting recipes already installed in the substrate processingapparatus. In the case of changing the recipes, the changed recipes maybe installed in the substrate processing apparatus via an electriccommunication line or a recording medium in which the recipes arerecorded. In addition, by operating the input/output device 122installed in the existing substrate processing apparatus, the existingrecipes already installed in the substrate processing apparatus may bedirectly changed.

In the above-described embodiment, there has been described an examplewhere the first to third suppliers are installed in the process chamberso as to extend along the inner wall of the reaction tube. However, thepresent disclosure is not limited to the embodiments described above.For example, as can be noted from the cross-sectional structure of thevertical process furnace shown in FIG. 5A, a buffer chamber may beinstalled in the side wall of the reaction tube, and in the bufferchamber, first to third suppliers having the same configuration as inthe above-described embodiment may be installed in the same arrangementas in the above-described embodiment. In FIG. 5A, there is shown anexample where a supply-purpose buffer chamber and an exhaust-purposebuffer chamber are installed in the side wall of the reaction tube andare disposed at positions facing each other across the wafers. Each ofthe supply-purpose buffer chamber and the exhaust-purpose buffer chamberis installed to extend from the lower portion to the upper portion ofthe side wall of the reaction tube, i.e., along the wafer arrangementregion. In addition, FIG. 5A shows an example where the supply-purposebuffer chamber is partitioned into a plurality of (three) spaces, andindividual nozzles are disposed in the respective spaces. Thearrangement of the three spaces of the buffer chamber is the same as thearrangement of the first to third suppliers. Furthermore, for example,as can be noted from the cross-sectional structure of the verticalprocess furnace shown in FIG. 5B, a buffer chamber may be installed inthe same arrangement as in FIG. 5A, a second supplier may be installedin the buffer chamber, and first and third suppliers may be installed soas to sandwich the communication portion, which communicates with theprocess chamber, of the buffer chamber from both sides of thecommunication portion and so as to extend along the inner wall of thereaction tube. The configurations other than the buffer chamber and thereaction tube described with reference to FIGS. 5A and 5B are the sameas the configurations of the respective parts of the process furnaceshown in FIG. 1. Even when these process furnaces are used, the sameeffects as those of the above-described embodiment are obtained.

In the above-described embodiment, there has been described an examplewhere a film is formed using a batch type substrate processing apparatusthat processes a plurality of substrates at a time. The presentdisclosure is not limited to the above-described embodiments, but may besuitably applied to, for example, a case where a film is formed using asingle-wafer type substrate processing apparatus that processes one orplural substrates at a time. Furthermore, in the above-describedembodiment, there has been described an example where a film is formedusing a substrate processing apparatus including a hot wall type processfurnace. The present disclosure is not limited to the above-describedembodiments, but may be suitably applied to a case where a film isformed using a substrate processing apparatus including a cold wall typeprocess furnace.

Even in the case of using these substrate processing apparatuses, filmformation can be performed under the same sequences and processingconditions as those of the above-described embodiment and modifications,and the same effects as described above are obtained.

Further, the above-described embodiment and modifications may be used incombination as appropriate. The processing procedures and processingconditions at this time may be the same as, for example, the processingprocedures and processing conditions of the above-described embodiment.

The various effects described in this specification are similarlyobtained not only when the formation of a film on a substrate isperformed under the conditions that the processing gas supplied to thesubstrate is thermally decomposed (under the conditions that aself-limit is not applied) but also when the formation of a film on asubstrate is performed under the conditions that the processing gassupplied to the substrate is not thermally decomposed (under theconditions that a self-limit is applied). However, the effect relatingto the adjustment of the in-plane film thickness distribution among thevarious effects described above is particularly effectively obtainedwhen the formation of a film on a substrate is performed under theconditions that the processing gas supplied to the substrate isthermally decomposed and the CVD reaction occurs.

[Example]

In sample A, using the substrate processing apparatus shown in FIG. 1, aSi film was formed on the wafer according to the film formation sequenceshown in FIG. 4. When performing the Si film formation step, the flowrate of the N₂ gas supplied from the first supplier was set to apredetermined flow rate within a range of 150 to 250 sccm and the flowrate of the N₂ gas supplied from the second supplier was set to apredetermined flow rate within a range of 40 to 80 sccm. Otherprocessing conditions were set to predetermined conditions fallingwithin the processing condition range described in the above embodiment.

In sample B, using the substrate processing apparatus shown in FIG. 1, aSi film was formed on the wafer according to the film formation sequenceshown in FIG. 4. When performing the Si film formation step, the flowrate of the N₂ gas supplied from the first supplier was set to apredetermined flow rate within a range of 450 to 550 sccm and the flowrate of the N₂ gas supplied from the second supplier was set to apredetermined flow rate within a range of 40 to 80 sccm. Otherprocessing conditions were the same as the processing conditions usedwhen preparing sample A.

In sample C, using the substrate processing apparatus shown in FIG. 1, aSi film was formed on the wafer according to the film formation sequenceshown in FIG. 4. However, when performing the Si film formation step,the balance of the flow rates of the N₂ gases supplied from the firstand second suppliers was reversed from that at the time of preparingsample A. Specifically, when performing the Si film formation step, theflow rate of the N₂ gas supplied from the first supplier was set to apredetermined flow rate within a range of 250 to 350 sccm and the flowrate of the N₂ gas supplied from the second supplier was set to apredetermined flow rate within a range of 700 to 900 sccm. Otherprocessing conditions were the same as the processing conditions usedwhen preparing sample A.

Then, the film thicknesses of the Si films of samples A to C weremeasured at the outer peripheral portion of the wafer and compared witheach other. FIG. 6A is a diagram for comparing the measurement resultsof samples A and B, and FIG. 6B is a diagram for comparing themeasurement results of samples A and C. The measurement positions (thedistances from the center of the wafer) of samples A and B in FIG. 6Aare positions corresponding to each other, and the measurement positions(the distances from the center of the wafer) of samples A and C in FIG.6B are also positions corresponding to each other. However, themeasurement positions of samples A and B in FIG. 6A and the measurementpositions of samples A and C in FIG. 6B are different positions in theouter peripheral portion of the wafer. Each of the vertical axes inFIGS. 6A and 6B indicates a film thickness (A), the horizontal axis inFIG. 6A indicates samples A and B, and the horizontal axis in FIG. 6Bindicates samples A and C.

According to FIG. 6A, it can be seen that the film thickness of the Sifilm of sample B at the outer peripheral portion of the wafer is smallerthan the film thickness of the Si film of sample A at the outerperipheral portion of the wafer. That is, when performing the Si filmformation step, by increasing the flow rate of the N₂ gas supplied fromthe first supplier, i.e., by increasing the ratio of the flow rate ofthe N₂ gas supplied from the first supplier to the flow rate of the N₂gas supplied from the second supplier, it is possible to adjust the filmthickness of the Si film formed on the outer peripheral portion of thewafer in a decreasing direction.

Further, according to FIG. 6B, it can be seen that the film thickness ofthe Si film of sample B at the outer peripheral portion of the wafer islarger than the film thickness of the Si film of sample A at the outerperipheral portion of the wafer. That is, when performing the Si filmformation step, by reversing the flow rate balance so as to make theflow rate of the N₂ gas supplied from the second supplier larger thanthe flow rate of the N₂ gas supplied from the first supplier, it ispossible to adjust the film thickness of the Si film formed on the outerperipheral portion of the wafer in an increasing direction.

From these results, it can be noted that, when performing the Si filmformation step, by controlling the balance between the flow rate of theN₂ gas supplied from the first supplier and the flow rate of the N₂ gassupplied from the second supplier, it is possible to adjust the in-planefilm thickness distribution of the Si film formed on the wafer over awide range and in a precise manner.

According to the present disclosure in some embodiments, it is possibleto control the substrate in-plane film thickness distribution of a filmformed on a substrate.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosures. Indeed, the embodiments described herein maybe embodied in a variety of other forms. Furthermore, various omissions,substitutions and changes in the form of the embodiments describedherein may be made without departing from the spirit of the disclosures.The accompanying claims and their equivalents are intended to cover suchforms or modifications as would fall within the scope and spirit of thedisclosures.

What is claimed is:
 1. A method of manufacturing a semiconductor device,comprising: providing a substrate; and forming a film containing a mainelement on the substrate by performing: supplying a first inert gas froma first supplier to the substrate; supplying a second inert gas from asecond supplier to the substrate; and supplying a first processing gascontaining the main element constituting the film from a third supplier,which is installed on an opposite side of the first supplier across astraight line passing through the second supplier and a center of thesubstrate, to the substrate, wherein the act of forming the film isperformed under a condition in which adsorption of the main element,which is contained in the first processing gas, on a surface of thesubstrate is not self-limited, and wherein in the act of forming thefilm, a substrate in-plane film thickness distribution of the filmformed on the substrate is adjusted by controlling a balance between aflow rate of the first inert gas supplied from the first supplier and aflow rate of the second inert gas supplied from the second supplier. 2.The method according to claim 1, wherein the flow rate of the firstinert gas supplied from the first supplier is different from the flowrate of the second inert gas supplied from the second supplier.
 3. Themethod according to claim 1, wherein the flow rate of the first inertgas supplied from the first supplier is larger than the flow rate of thesecond inert gas supplied from the second supplier.
 4. The methodaccording to claim 1, wherein the flow rate of the first inert gassupplied from the first supplier is smaller than the flow rate of thesecond inert gas supplied from the second supplier.
 5. The methodaccording to claim 1, further comprising: after the act of providing thesubstrate and before the act of forming the film, forming a seed layeron the substrate by supplying a second processing gas from the firstsupplier to the substrate, supplying the second inert gas from thesecond supplier to the substrate, and supplying a third inert gas fromthe third supplier to the substrate, wherein in the act of forming theseed layer, a substrate in-plane thickness distribution of the seedlayer formed on the substrate is adjusted by controlling a balancebetween a flow rate of the second inert gas supplied from the secondsupplier and a flow rate of the third inert gas supplied from the thirdsupplier.
 6. The method according to claim 1, further comprising: afterthe act of providing the substrate and before the act of forming thefilm, forming a seed layer on the substrate by supplying the first inertgas from the first supplier to the substrate, supplying the second inertgas from the second supplier to the substrate, and supplying a secondprocessing gas from the third supplier to the substrate, wherein in theact of forming the seed layer, a substrate in-plane thicknessdistribution of the seed layer formed on the substrate is adjusted bycontrolling a balance between a flow rate of the first inert gassupplied from the first supplier and a flow rate of the second inert gassupplied from the second supplier.
 7. The method according to claim 1,wherein when seen in a plan view, the second supplier is disposed toface an exhaust port configured to exhaust the respective gases acrossthe substrate interposed between the second supplier and the exhaustport, and the first supplier and the third supplier are disposed so asto sandwich a straight line, which passes through the second supplierand the exhaust port.
 8. The method according to claim 5, wherein theflow rate of the second inert gas supplied from the second supplier isdifferent from the flow rate of the third inert gas supplied from thethird supplier.
 9. The method according to claim 5, wherein the flowrate of the second inert gas supplied from the second supplier issmaller than the flow rate of the third inert gas supplied from thethird supplier.
 10. The method according to claim 5, wherein the flowrate of the second inert gas supplied from the second supplier is largerthan the flow rate of the third inert gas supplied from the thirdsupplier.
 11. The method according to claim 5, wherein in the act offorming the seed layer, a cycle is performed a predetermined number oftimes, the cycle including alternately performing: supplying a thirdprocessing gas from any one of the first supplier, the second supplierand the third supplier to the substrate; and supplying the secondprocessing gas from the first supplier to the substrate, supplying thesecond inert gas from the second supplier to the substrate, andsupplying the third inert gas from the third supplier to the substrate.12. The method according to claim 11, wherein in the act of supplyingthe third processing gas, the first inert gas is supplied from the firstsupplier to the substrate, the third processing gas is supplied from thesecond supplier to the substrate, and the third inert gas is suppliedfrom the third supplier to the substrate.
 13. The method according toclaim 6, wherein the flow rate of the first inert gas supplied from thefirst supplier is different from the flow rate of the second inert gassupplied from the second supplier.
 14. The method according to claim 6,wherein the flow rate of the first inert gas supplied from the firstsupplier is larger than the flow rate of the second inert gas suppliedfrom the second supplier.
 15. The method according to claim 6, whereinthe flow rate of the first inert gas supplied from the first supplier issmaller than the flow rate of the second inert gas supplied from thesecond supplier.
 16. The method according to claim 6, wherein in the actof forming the seed layer, a cycle is performed a predetermined numberof times, the cycle including alternately performing: supplying a thirdprocessing gas from any one of the first supplier, the second supplierand the third supplier to the substrate; and supplying the first inertgas from the first supplier to the substrate, supplying the second inertgas from the second supplier to the substrate, and supplying the secondprocessing gas from the third supplier to the substrate.
 17. The methodaccording to claim 16, wherein in the act of supplying the thirdprocessing gas, the first inert gas is supplied from the first supplierto the substrate, the third processing gas is supplied from the secondsupplier to the substrate, and a third inert gas is supplied from thethird supplier to the substrate.
 18. The method according to claim 7,wherein the first supplier and the third supplier are line-symmetricallydisposed with respect to the straight line, as a symmetry axis, passingthrough the second supplier and the exhaust port.
 19. A substrateprocessing apparatus, comprising: a process chamber in which a substrateis processed; a first supply system configured to supply a first inertgas from a first supplier to the substrate in the process chamber; asecond supply system configured to supply a second inert gas from asecond supplier to the substrate in the process chamber; a third supplysystem installed on an opposite side of the first supplier across astraight line passing through the second supplier and a center of thesubstrate, and configured to supply a processing gas from a thirdsupplier to the substrate in the process chamber, the processing gascontaining a main element that constitutes a film to be formed; and acontroller configured to control the first supply system, the secondsupply system and the third supply system so as to form the filmcontaining the main element on the substrate by performing: supplyingthe first inert gas from the first supplier to the substrate, supplyingthe second inert gas from the second supplier to the substrate, andsupplying the processing gas from the third supplier to the substrate ina state in which the substrate is provided in the process chamber,wherein the act of forming the film is performed under a condition inwhich adsorption of the main element, which is contained in theprocessing gas, on a surface of the substrate is not self-limited, andwherein in the act of forming the film, a substrate in-plane filmthickness distribution of the film formed on the substrate is adjustedby controlling a balance between a flow rate of the first inert gassupplied from the first supplier and a flow rate of the second inert gassupplied from the second supplier.
 20. A non-transitorycomputer-readable recording medium storing a program that causes, by acomputer, a substrate processing apparatus to perform: providing asubstrate in a process chamber of the substrate processing apparatus;forming a film containing a main element on the substrate in the processchamber by performing: supplying a first inert gas from a first supplierto the substrate; supplying a second inert gas from a second supplier tothe substrate; and supplying a processing gas containing the mainelement constituting the film from a third supplier, that is installedon an opposite side of the first supplier across a straight line passingthrough the second supplier and a center of the substrate, to thesubstrate; and adjusting a substrate in-plane film thicknessdistribution of the film formed on the substrate by controlling abalance between a flow rate of the first inert gas supplied from thefirst supplier and a flow rate of the second inert gas supplied from thesecond supplier in the act of forming the film, wherein the act offorming the film is performed under a condition in which adsorption ofthe main element, which is contained in the processing gas, on a surfaceof the substrate is not self-limited.